I found this old blog with some ideas that might be new to you.
Did you know that you could buy washable "Window Markers" and "Chalk Markers" that will work on windows and mirrors. (I actually found these on Amazon.) They would be great to put on a Christmas "wish list"!
As a teacher, here are some uses for the markers in your classroom:
Reading
Write letters, words, numerals, shapes, or anything you want to reinforce on windows or mirrors.
*Let children wear sunglasses and identify the information with a pointer.
Writing
Let children practice writing letters, numerals, spelling words, etc. on classroom windows.
* How about rainbow writing? Make giant letters, shapes, words, etc. on windows. Children can take the markers and trace around the figures with different colors.
Reward
Use these as a reward or when children finish their work early.
Reminders
Use the classroom mirror as a message board to write words of encouragement, reminders, or to celebrate accomplishments.
Special Days
Let children decorate classroom windows for holidays, seasons, themes, or other special events.
Brainstorm!
Write a word or theme and invite children to add their own thoughts to the window.
Sign In
Children can write their name or a special message when they come to school each morning.
Graffiti
What an open-ended art center this could be throughout the year!
Mirror! Mirror!
Write a sight word or vocabulary word on the mirror each day.
Write a positive thought on the mirror.
Let children decorate the mirror on their birthday.